A postal service company and a courier service company perform work of sorting collected parcels, packages, and the like by destination. For example, collected packages and the like are gathered in a specific sorting area, where they are sorted by destination and loaded onto a truck or the like. In the sorting area, conveyor lines are provided vertically and horizontally, and the collected packages are gathered according to destination. Here, in the conveyor line in the sorting area, a plurality of auxiliary conveying passages (child conveying passages) are branched from a main conveying passage, and further a plurality of auxiliary conveying passages (grandchild conveying passages) and great-grandchild conveying passages are branched.
Further, in recent years, the sorting is performed more in detail, and there is a situation where a conveyor line needs to be further complicated. For this reason, the conveyor line is assembled three-dimensionally, a horizontal conveying passage is provided above or below another horizontal conveying passage, and a package is transferred between the upper and lower horizontal conveying passages. As a lifting device used for such an application, for example, there is one that lifts and lowers a lifting and lowering table with a pantograph mechanism. Further, Patent Document 1 discloses an invention in which a wire rope is suspended on a pulley provided with a drive motor, and a frame-type carriage connected to the wire rope is moved up and down in a height direction to convey a conveyance object.